Table 1.

Distribution pattern of expressed protein in nuclear (N) and cytoplasmic (C) compartments^a

Protein(s) expressed	Plasmid amt (μg) or ratiob	% of cells expressing indicated protein(s)
		GFP (combined with Btk, Btk-NLS, or Btk-ΔSH3-NLS)			DsRed-Liar
		N only	C only	Both N and C	N only	C only	Both N and C
DsRed-Liar	0.8				18	0	82
Btk-GFP	0.8	0	93	7
GFP-Btk	0.8	0	94	6
GFP-Btk-NLS	0.8	100c	0	0
GFP–Btk-ΔSH3-NLS	0.8	100c	0	0
DsRed-Liar + GFP-Btk	1:1d	0	100	0	23	0	77
DsRed-Liar + GFP-Btk-NLS	1:1d	0	100	0	10	0	90
DsRed-Liar + GFP–Btk-ΔSH3-NLS	1:1d	100	0	0	22	0	78
DsRed-Liar	0.3				56	0	44
DsRed-Liar + GFP-Btk-NLS + Btk-SH3	1:1:8e	18	56	26	0	62	38
DsRed-Liar + GFP–Btk-ΔSH3-NLS + Btk-SH3	1:1:8e	100	0	0	0	37	63
		Btk-SH3			DsRed-Liar
Btk-SH3	0.8	0	0	100
DsRed-Liar + Btk-SH3	1:1	0	95	5	0	0	100

^aDistribution of DsRed-Liar protein alone or in the presence of Btk-GFP, GFP-Btk, GFP-Btk-NLS, or GFP–Btk-ΔSH3-NLS is shown. In some experiments, the Btk SH3 domain was utilized as a competitor for the Btk-Liar interaction. Mean values were calculated for 100 to 300 cells from three separate experiments.

^bPlasmid amounts and cotransfection ratios are indicated.

^cAlmost entirely nuclear-resident Btk, but with a small fraction of overexpressed Btk being localized in the cytoplasm and around the nucleus.

^d1 = 0.8 μg of plasmid.

^e1 = 0.3 μg of plasmid (an amount used to reach similar total levels of transfected plasmid).